Human Growth and Development

Experimental Setup: ●​ Three groups of children are randomly assigned different physical activity levels: 1.​ Control group: No physical activity beyond their regular school routine. 2.​ Moderate activity group: 30 minutes of structured exercise daily. 3.​ High activity group: 60 minutes of structured exercise daily. ●​ After a set period (e.g., 8 weeks), all children undergo cognitive testing. The researcher compares their test scores to determine if varying levels of physical activity had a significant effect on memory and attention. This design helps ensure that the relationship between physical activity (IV) and cognitive performance (DV) can be properly analyzed, minimizing the influence of extraneous variables like prior physical fitness levels or differences in schooling environments. There are two types of experiments: true experiments and quasi-experiments.

Feature

True Experiment

Quasi-Experiment

Internal Validity

High

Moderate

External Validity

Low

Moderate-High

Hypothesis

Clear and testable

Exploratory or descriptive

Participant Assignment

Random

Non-random (existing groups)

Independent Variable

Manipulated

May not be fully controlled

Correlational Correlation is a statistical relationship between two variables. It means that when one variable changes, the other also changes in some way. However, correlation does not mean causation —just because two things are related does not mean one causes the other. A third factor may be responsible for both. For example, while there may be a correlation between ice cream consumption and swimming pool accidents, hot weather is likely the cause, increasing both ice cream sales and the number of people swimming.

© 2025 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE | HUMAN GROWTH AND DEVELOPMENT